I am interested in ultrafast and nonlinear phenomena in condensed matter, in particular organic and inorganic solids and nanostructures. To this end, I generate and apply ultrashort pulses in a wide spectral range (THz to hard x-ray) to measure the nonequilibrium dynamics of elementary excitations in solids and the ultrafast structural dynamics of crystalline material. Most recent activities are two-dimensional spectroscopy in the THz frequency range (Figure: two phonon coherences in InSb) and femtosecond x-ray absorption experiments using table top high harmonic sources.